Not Applicable
Not Applicable
Not Applicable
1. Field of the Invention
The present invention relates to a broadcasting receiving system for receiving a digital broadcasting and storing the same, and more particularly, to a copy prevention apparatus and method in a digital broadcasting receiving system in which an unauthorized illegal copy of a broadcasting signal whose copyright should be protected is prevented when the broadcasting signal is stored in a storage medium.
2. Description of the Related Art
A hard disk drive (HDD) is an auxiliary storage device for use in computers, in which random access is possible, data transfer speed is high and its cost is lowerer than other auxiliary storage devices, to thereby however realize a large capacity. Recently, a digital versatile disc (DVD) is favored as a next-generation storage medium. A recent form of the DVD is a DVD-RAM free of recording and deletion of data. Accordingly, the HDD or DVD-RAM drive is used as a storage device in a broadcasting receiving system, to thereby enable a user to view a broadcasting program or store the same.
Meanwhile, a digital broadcasting employing a multi-channel and containing a plurality of programs for each channel has started. A digital broadcasting receiving system receives multi-channel digital audio/video data transmitted via a broadcasting station or network and reproduces and stores the received data. Generally, digital audio/video data is encoded by the MPEG (moving picture expert group) standard and is transmitted in the form of a digital transport stream (TS) packetized including data of a number of programs. Here, the data of the programs is encoded by an encryption or scramble method, and decoded only in a broadcasting receiving system where a view of programs is allowed.
The above-described prior art reference will be described in more detail with reference to FIG. 1 showing a schematic structure of a broadcasting receiving system adopting a general HDD.
In FIG. 1, a TS demultiplexer 100 extracts a key of an encrypted scrambler from data TS1 of an input scrambled TS pattern. The TS demultiplexer 100 decrypts a scrambler key extracted according to user information programmed in advance on a smart card 104. The decrypted scrambler key and the input TS patterned data TS1 are input to a descrambler 102. The descrambler 102 decrambles the input TS patterned data TS1 using a decrypted key applied from the TS demultiplexer 100. The descrambled TS patterned data TS2 is input to an audio/video (A/V) decoder 106 or a HDD interface unit 110 via the TS demultiplexer 100 under the control of a system controller 108 responding to a reproduction or storing request from a user. In the case that a user requests a reproduction operation, the A/V decoder 106 decodes the input descrambled TS patterned data TS2 to be displayed so that the user can view it. In the case that a user requests a storing operation, the HDD interface unit 110 stores the input descrambled TS patterned data TS2 in a HDD (not shown).
However, the above-described conventional broadcasting receiving system stores a broadcasting signal in the descrambled form when it is stored in a storage medium. For this reason, the contents of the storage medium are copied by an unauthorized third party, in which case the stored information cannot be protected from being illegally distributed.
To solve the above problems, it is an object of the present invention to provide a copy prevention apparatus and method for protecting stored information in a storage medium from being illegally duplicated by an unauthorized third party in which a broadcasting signal is scrambled when a broadcasting received from a digital broadcasting receiving system is stored in the storage medium.
To accomplish the above object of the present invention, there is provided a copy prevention apparatus for use in a digital broadcasting receiving system for receiving a digital multi-channel broadcasting and viewing and storing a desired program, the copy prevention apparatus comprising: a descrambler for extracting an encrypted key of a scrambler from scrambled transport stream (TS) patterned data received in correspondence to a desired channel, decrypting the extracted encrypted key, and descrambling the scrambled TS patterned data using the decrypted key; a scrambler for scrambling the descrambled TS patterned data again; a key encryption unit for decrypting the encrypted key of the scrambler and encrypting the decrypted key again, to thereby produce a new encryption key; a storage medium for storing the scrambled TS patterned data together with the produced encryption key; and a system controller for controlling the operation of each component so that data is stored after a copy prevention operation has been performed in response to a storing request from a user.
There is also provided a method for preventing a storage medium from being illegally copied in a digital broadcasting receiving system, the copy prevention method the steps of: (a) extracting an encrypted key of a scrambler from input scrambled transport stream (TS) patterned data; (b) decrypting the scrambler key extracted in step (a) and descrambling the scrambled TS patterned data using the decrypted key; (c) scrambling the descrambled TS patterned data again from step (b) in response to a storing request from a user, decrypting the encrypted scrambler key again and encrypting the decrypted key again, to thereby produce a new encryption key; and (d) storing the scrambled TS patterned data together with the encryption key produced in step (c).